Análisis del gen adra2a receptor alfa 2a adrenergico en pacientes con trastorno de hiperactividad y déficit de atención

El trastorno de hiperactividad y déficit de atención (THDA), es definido clínicamente como una alteración en el comportamiento, caracterizada por inatención, hiperactividad e impulsividad. Estos aspectos son clasificados en tres subtipos, que son: Inatento, hiperactivo impulsivo y mixto. Clínicamente se describe un espectro amplio que incluye desordenes académicos, trastornos de aprendizaje, déficit cognitivo, trastornos de conducta, personalidad antisocial, pobres relaciones interpersonales y aumento de la ansiedad, que pueden continuar hasta la adultez. A nivel global se ha estimado una prevalencia entre el 1% y el 22%, con amplias variaciones, dadas por la edad, procedencia y características sociales. En Colombia, se han realizado estudios en Bogotá y Antioquia, que han permitido establecer una prevalencia del 5% y 15%, respectivamente. La causa específica no ha sido totalmente esclarecida, sin embargo se ha calculado una heredabilidad cercana al 80% en algunas poblaciones, demostrando el papel fundamental de la genética en la etiología de la enfermedad. Los factores genéticos involucrados se relacionan con cambios neuroquímicos de los sistemas dopaminérgicos, serotoninérgicos y noradrenérgicos, particularmente en los sistemas frontales subcorticales, corteza cerebral prefrontal, en las regiones ventral, medial, dorsolateral y la porción anterior del cíngulo. Basados en los datos de estudios previos que sugieren una herencia poligénica multifactorial, se han realizado esfuerzos continuos en la búsqueda de genes candidatos, a través de diferentes estrategias. Particularmente los receptores Alfa 2 adrenérgicos, se encuentran en la corteza cerebral, cumpliendo funciones de asociación, memoria y es el sitio de acción de fármacos utilizados comúnmente en el tratamiento de este trastorno, siendo esta la principal evidencia de la asociación de este receptor con el desarrollo del THDA. Hasta la fecha se han descrito más de 80 polimorfismos en el gen (ADRA2A), algunos de los cuales se han asociado con la entidad. Sin embargo, los resultados son controversiales y varían según la metodología diagnóstica empleada y la población estudiada, antecedentes y comorbilidades. Este trabajo pretende establecer si las variaciones en la secuencia codificante del gen ADRA2A, podrían relacionarse con el fenotipo del Trastorno de Hiperactividad y el Déficit de Atención.

An Earth Observation Land Data Assimilation System (EO-LDAS)

Current methods for estimating vegetation parameters are generally sub-optimal in the way they exploit information and do not generally consider uncertainties. We look forward to a future where operational dataassimilation schemes improve estimates by tracking land surface processes and exploiting multiple types of observations. Dataassimilation schemes seek to combine observations and models in a statistically optimal way taking into account uncertainty in both, but have not yet been much exploited in this area. The EO-LDAS scheme and prototype, developed under ESA funding, is designed to exploit the anticipated wealth of data that will be available under GMES missions, such as the Sentinel family of satellites, to provide improved mapping of land surface biophysical parameters. This paper describes the EO-LDAS implementation, and explores some of its core functionality. EO-LDAS is a weak constraint variational dataassimilationsystem. The prototype provides a mechanism for constraint based on a prior estimate of the state vector, a linear dynamic model, and EarthObservationdata (top-of-canopy reflectance here). The observation operator is a non-linear optical radiative transfer model for a vegetation canopy with a soil lower boundary, operating over the range 400 to 2500 nm. Adjoint codes for all model and operator components are provided in the prototype by automatic differentiation of the computer codes. In this paper, EO-LDAS is applied to the problem of daily estimation of six of the parameters controlling the radiative transfer operator over the course of a year (> 2000 state vector elements). Zero and first order process model constraints are implemented and explored as the dynamic model. The assimilation estimates all state vector elements simultaneously. This is performed in the context of a typical Sentinel-2 MSI operating scenario, using synthetic MSI observations simulated with the observation operator, with uncertainties typical of those achieved by optical sensors supposed for the data. The experiments consider a baseline state vector estimation case where dynamic constraints are applied, and assess the impact of dynamic constraints on the a posteriori uncertainties. The results demonstrate that reductions in uncertainty by a factor of up to two might be obtained by applying the sorts of dynamic constraints used here. The hyperparameter (dynamic model uncertainty) required to control the assimilation are estimated by a cross-validation exercise. The result of the assimilation is seen to be robust to missing observations with quite large data gaps.

Effects of oxidised low density lipoprotein on dendritic cells: a possible immunoregulatory component of the atherogenic micro-environment?

Objective: The objective of this study was to explore the relationship between low density lipoprotein (LDL) and dendritic cell (DC) activation, based upon the hypothesis that reactive oxygen species (ROS)-mediated modification of proteins that may be present in local DC microenvironments could be important as mediators of this activation. Although LDL are known to be oxidised in vivo, and taken up by macrophages during atherogenesis; their effect on DC has not been explored previously. Methods: Human DCs were prepared from peripheral blood monocytes using GM-CSF and IL-4. Plasma LDLs were isolated by sequential gradient centrifugation, oxidised in CuSO4, and oxidation arrested to yield mild, moderate and highly oxidised LDL forms. DCs exposed to these LDLs were investigated using combined phenotypic, functional (autologous T cell activation), morphological and viability assays. Results: Highly-oxidised LDL increased DC HLA-DR, CD40 and CD86 expression, corroborated by increased DC-induced T cell proliferation. Both native and oxidised LDL induced prominent DC clustering. However, high concentrations of highly-oxidised LDL inhibited DC function, due to increased DC apoptosis. Conclusions: This study supports the hypothesis that oxidised LDL are capable of triggering the transition from sentinel to messenger DC. Furthermore, the DC clustering–activation–apoptosis sequence in the presence of different LDL forms is consistent with a regulatory DC role in immunopathogenesis of atheroma. A sequence of initial accumulation of DC, increasing LDL oxidation, and DC-induced T cell activation, may explain why local breach of tolerance can occur. Above a threshold level, however, supervening DC apoptosis limits this, contributing instead to the central plaque core.

Contribution of fimbriae and flagella of Salmonella enteritidis to colonization and invasion of chicks

Isogenic mutants of Salmonella enteritidis defective for the elaboration of fimbrial types SEF14, SEF17, SEF21 and flagella were used to study the contribution these organelles made to colonization, invasion and lateral transfer in young chicks. The caecum, liver and spleen were colonized within 24 h following oral inoculation of 1-day-old chicks with 10(5) wild-type S. enteritidis strain LA5. However, for some mutants, the numbers of organisms recovered from internal organs was reduced significantly, particularly at 24 h post-inoculum, which supported the hypothesis that the organelles contribute to invasion and dissemination to internal organs. Specifically, mutations affecting SEF17, SEF21 and flagella contributed to a delay in colonization of the spleen, and those affecting SEF21 and flagella delayed colonization of the liver. Lower numbers of bacteria were recovered from the caecum with mutants deficient in elaboration of SEF21. Sentinel birds were colonized by LA5 or EAV40 (14(-), 17(-), 21(-), fla(-)) directly from the environment within 2 days, although a consistent slight delay was observed with the multiple mutant. Overall, our data suggest a collective role for SEF17, SEF21 and flagella, but not SEF14, in the early stages of colonization and invasion of young chicks by S. enteritidis, but these surface appendages appear unnecessary for colonization of birds from their immediate environment.

Cooled infrared filters and dichroics for the sea and land surface temperature radiometer (SLSTR)

The Sea and Land Surface Temperature Radiometer (SLSTR) is a nine channel visible and infrared high precision radiometer designed to provide climate data of global sea and land surface temperatures. The SLSTR payload is destined to fly on the Ocean and Medium-Resolution Land Mission for the ESA/EU Global Monitoring for Environment and Security (GMES) Programme Sentinel-3 mission to measure the sea and land temperature and topography for near real-time environmental and atmospheric climate monitoring of the Earth. In this paper we describe the optical layout of infrared optics in the instrument, spectral thin-film multilayer design, and system channel throughput analysis for the combined interference filter and dichroic beamsplitter coatings to discriminate wavelengths at 3.74, 10.85 & 12.0 μm. The rationale for selection of thin-film materials, deposition technique, and environmental testing, inclusive of humidity, thermal cycling and ionizing radiation testing are also described.

A low-cost wireless temperature sensor: evaluation for use in environmental applications

With a wide range of applications benefiting from dense network air temperature observations but with limitations of costs, existing siting guidelines and risk of damage to sensors, new methods are required to gain a high resolution understanding of the spatio-temporal patterns of urban meteorological phenomena such as the urban heat island or precision farming needs. With the launch of a new generation of low cost sensors it is possible to deploy a network to monitor air temperature at finer spatial resolutions. Here we investigate the Aginova Sentinel Micro (ASM) sensor with a bespoke radiation shield (together < US$150) which can provide secure near-real-time air temperature data to a server utilising existing (or user deployed) Wireless Fidelity (Wi-Fi) networks. This makes it ideally suited for deployment where wireless communications readily exist, notably urban areas. Assessment of the performance of the ASM relative to traceable standards in a water bath and atmospheric chamber show it to have good measurement accuracy with mean errors < ± 0.22 °C between -25 and 30 °C, with a time constant in ambient air of 110 ± 15 s. Subsequent field tests of it within the bespoke shield also had excellent performance (root-mean-square error = 0.13 °C) over a range of meteorological conditions relative to a traceable operational UK Met Office platinum resistance thermometer. These results indicate that the ASM and bespoke shield are more than fit-for-purpose for dense network deployment in urban areas at relatively low cost compared to existing observation techniques.

Cloud clearing techniques over land for land surface temperature retrieval from the Advanced Along Track Scanning Radiometer

We present five new cloud detection algorithms over land based on dynamic threshold or Bayesian techniques, applicable to the Advanced Along Track Scanning Radiometer (AATSR) instrument and compare these with the standard threshold based SADIST cloud detection scheme. We use a manually classified dataset as a reference to assess algorithm performance and quantify the impact of each cloud detection scheme on land surface temperature (LST) retrieval. The use of probabilistic Bayesian cloud detection methods improves algorithm true skill scores by 8-9 % over SADIST (maximum score of 77.93 % compared to 69.27 %). We present an assessment of the impact of imperfect cloud masking, in relation to the reference cloud mask, on the retrieved AATSR LST imposing a 2 K tolerance over a 3x3 pixel domain. We find an increase of 5-7 % in the observations falling within this tolerance when using Bayesian methods (maximum of 92.02 % compared to 85.69 %). We also demonstrate that the use of dynamic thresholds in the tests employed by SADIST can significantly improve performance, applicable to cloud-test data to provided by the Sea and Land Surface Temperature Radiometer (SLSTR) due to be launched on the Sentinel 3 mission (estimated 2014).

Hospital-based Surveillance to Evaluate the Impact of Rotavirus Vaccination in Sao Paulo, Brazil

Background: Brazil implemented routine immunization with the human rotavirus vaccine, Rotarix, in 2006 and vaccination coverage reached 81% in 2008 in Sao Paulo. Our aim was to assess the impact of immunization on the incidence of severe rotavirus acute gastroenteritis (AGE). Methods: We performed a 5-year (2004-2008) prospective surveillance at a sentinel hospital in Sao Paulo, with routine testing for rotavirus in all children less than 5 years of age hospitalized with AGE. Genotypes of positive samples were determined by reverse transcription polymerase chain reaction. Results: During the study, 655 children hospitalized with AGE were enrolled; of whom 169 (25.8%) were positive for rotavirus. In the post-vaccine period, a 59% reduction in the number of hospitalizations of rotavirus AGE and a 42.2% (95% confidence interval [CI], 18.6%-59.0%; P = 0.001) reduction in the proportion of rotavirus-positive results among children younger than 5 years were observed, with the greatest decline among infants (69.2%; 95% CI, 24.7%-87.4%; P = 0.004). Furthermore, the number of all-cause hospitalizations for AGE was reduced by 29% among children aged <5 years. The onset and peak incidences of rotavirus AGE occurred 3 months later in the 2007 and 2008 seasons compared with previous years. Genotype G2 accounted for 15%, 70%, and 100% of all cases identified, respectively, in 2006, 2007, and 2008. Conclusions: After vaccine implementation, a marked decline in rotavirus AGE hospitalizations was demonstrated among children younger than 5 years of age, with the greatest reduction in the age groups targeted for vaccination. The predominance of genotype G2P[4] highlights the need of continued postlicensure surveillance studies.

Species diversity of Leishmania (Viannia) parasites circulating in an endemic area for cutaneous leishmaniasis located in the Atlantic rainforest region of northeastern Brazil

OBJECTIVES To identify the aetiological agents of cutaneous leishmaniasis and to investigate the genetic polymorphism of Leishmania (Viannia) parasites circulating in an area with endemic cutaneous leishmaniasis (CL) in the Atlantic rainforest region of northeastern Brazil. METHODS Leishmania spp. isolates came from three sources: (i) patients diagnosed clinically and parasitologically with CL based on primary lesions, secondary lesions, clinical recidiva, mucocutaneous leishmaniasis and scars; (ii) sentinel hamsters, sylvatic or synanthropic small rodents; and (iii) the sand fly species Lutzomyia whitmani. Isolates were characterised using monoclonal antibodies, multilocus enzyme electrophoresis (MLEE) and polymerase chain reaction-restriction fragment length polymorphism of the internal transcribed spacer region rDNA locus. RESULTS Seventy-seven isolates were obtained and characterised. All isolates were identified as Leishmania (Viannia) braziliensis serodeme 1 based on reactivity to monoclonal antibodies. MLEE identified 10 zymodemes circulating in the study region. Most isolates were classified as zymodemes closely related to L. (V.) braziliensis, but five isolates were classified as Leishmania (Viannia) shawi. All but three of the identified zymodemes have so far been observed only in the study region. Enzootic transmission and multiclonal infection were observed. CONCLUSIONS Our results confirm that transmission cycle complexity and the co-existence of two or more species in the same area can affect the level of genetic polymorphism in a natural Leishmania population. Although it is not possible to make inferences as to the modes of genetic exchange, one can speculate that some of the zymodemes specific to the region are hybrids of L. (V.) braziliensis and L. (V.) shawi.

Identificação do linfonodo-sentinela em pacientes com carcinoma de colo uterino invasor estádio I-B 1

Objetivo: determinar a viabilidade da identificação do linfonodo-sentinela em pacientes com câncer invasor de colo uterino estádio Ib1. Material e Métodos: 16 pacientes consecutivas com câncer de colo uterino agendadas para histerectomia radical com linfadenectomia pélvica bilateral realizaram estudo para detecção de linfonodo-sentinela. Onze pacientes injetaram 1 mCi de tecnécio 99 (99Tc) em quatro pontos do estroma superficial do colo uterino ao redor do tumor, às 12, 3, 6 e 9 h ( 16 horas antes da cirurgia ). No dia da cirurgia, as pacientes foram submetidas ao mapeamento linfático com gamma-probe e azul patente injetado nos mesmos pontos que o 99Tc.Cinco pacientes realizaram a detecção apenas com azul patente. Resultados: foi detectado pelo menos um (1 a 3 por paciente) linfonodo-sentinela em cada uma das 15 pacientes (93,7 %) que realizaram a técnica combinada.Foi detectado pelo menos 1 linfonodo-sentinela em 4 pacientes ( 80% )com azul patente apenas. A maioria dos linfonodos-sentinela foi localizada nas regiões: obturadora (37 %), ilíaca externa (22,2 %) e inter-ilíacas (18,5 %). Seis pacientes (40 %) tiveram linfonodos-sentinela bilaterais. Dos 27 linfonodos-sentinela detectados, 11 (40,7 %) foram detectados pelo corante, 9 (33,3%) pela radioatividade e 7 (26 %) pela radioatividade e corante. O índice de detecção intra-operatória com o gamma-probe foi de 90,9 % ( 11 pacientes ). Destes, 7 linfonodos foram azul e quente (31,8 %), 6 linfonodos foram apenas azuis (27,2 %) e 9 linfonodos foram apenas quentes (40,9 %). A sensibilidade, especificidade e valor preditivo negativo para a detecção do linfonodo-sentinela foram 100%, 85,7 % e 100 % respectivamente. Conclusão: A combinação do radiofármaco 99Tc e azul patente é efetiva na detecção do linfonodosentinela em câncer de colo uterino inicial.

Nose-to-nose transmission of Salmonella Typhimurium between weaned pigs

Little attention has been paid to the possibility of transmission of Salmonella in intensive pig production systems through alternate methods, such as airborne or direct nose-to-nose contact. This experimental study tested the hypothesis of nose-to-nose transmission of Salmonella enterica serovars Typhimurium (Trial I) and Agona (Trial II) in weaned pigs using stainless steel/ glass isolation cabinets. In each trial, cabinet 1 (control pigs) and cabinet 2 (sentinel pigs) were connected directly to the fan unit. Cabinet 3 (seeded pigs) was not directly linked to the fan, but was arranged to receive a constant unidirectional airflow from cabinet 2 (sentinel pigs) through a 10 cm diameter hole, which also allowed nose-to-nose contact between pigs housed in these two cabinets. Air was taken out of the system through ducts connecting cabinets 1 and 3 to the exhauster. Therefore, direct contact among seeded and sentinel pigs was allowed but possible aerial transference of contaminated particles between those cabinets was prevented. The system was opened 21 days post-inoculation and tissue samples were collected for bacteriological analysis. The recovery of nalidixic acid-resistant Salmonella Typhimurium from sentinel pigs corroborates the hypothesis of nose-to-nose transmission of that pathogen in pigs. However, serovar-related differences might exist regarding the nose-to-nose transmissibility of Salmonella in pigs, since Salmonella Agona was not detected in sentinel pigs (Trial II). Published by Elsevier B.V.

Maize-Dwelling insects omnivory in Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) egg masses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Experimental airborne transmission of Salmonella Agona and Salmonella Typhimurium in weaned pigs

This study tested the hypothesis of airborne transmission of Salmonella Agona (Trial I) and Salmonella Typhimurium (Trial II) in weaned pigs. The trials were performed using stainless-steel/glass isolation cabinets connected by air ducts to permit an unidirectional airflow from cabinet 1 (two control pigs) to cabinet 3 (two sentinel pigs), passing through cabinet 2 (two inoculated pigs). Air samples, pooled faecal samples from the floor and rectal swabs were collected daily and assessed by culture and PCR. A fumigation chamber and rubber gloves coupled to the cabinets allowed sampling without opening the system. Trials I and II lasted 15 and 19 days respectively. The recovery of S. Agona and S. Typhimurium and detection of scroconversion in sentinel pigs indicate that airborne Salmonella transmission in weaned pigs over short distances is possible. Further studies on the role of aerosols in the epidemiology of Salmonella in intensive pig production should be performed.

Protection levels of vaccinated pigeons (Columba livia) against a highly pathogenic newcastle disease virus strain

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Experimental infection of Newcastle disease virus in pigeons (Columba livia): Humoral antibody response, contact transmission and viral genome shedding

The aim of this study was to evaluate the humoral antibody response, the genome viral excretion and the contact transmission of pathogenic chicken origin Newcastle disease virus (NDV) from experimentally infected pigeons (Columba livia) to in-contact pigeon. The antibody response to infection was assessed by the hemagglutination inhibition (HI) test and the genome viral excretion was detected by RT-PCR. Viral strain induced high antibody levels, both in inoculated and in sentinel birds. The pathogenic viral strain for chickens was unable to produce clinical signs of the disease in experimentally infected pigeons, although it induced the Immoral antibody response and produced NDV genome shedding. NDV genome was detected intermittently throughout the experimental period, from 5 days post-infection (dpi) to 24 dpi. Therefore, viral genome shedding occurred for 20 days. The viral genome was detected in all birds, between I I and 13 dpi. Furthermore, the high infectivity of the virus was confirmed, as all non-inoculated sentinel pigeons showed antibody levels as high as those of inoculated birds. (C) 2007 Elsevier B.V. All rights reserved.